This invention relates generally to the treatment of living beings, and more particularly to the treatment of conditions such as tumors in humans and other animals.
Conditions such as tumors in living bodies are treated non-surgically by a variety of different methods, including chemotherapy, radiation therapy, hyperthermia, and combinations thereof. These methods have as their objective the selective destruction of tumor cells. Hyperthermia, for example, which involves the application of heat to an affected area of the body, is based upon the principle that certain tumor cells have a lower temperature tolerance than normal healthy cells. Consequently, such tumor cells can be destroyed by elevating their temperature to a predetermined level above the normal body temperature. It is known that the cells of certain types of tumors can be destroyed by heating them to temperatures of the order of 110.degree. F. Hyperthermic treatment of tumors may be accomplished by perfusion techniques, as by irrigating a body cavity adjacent to the tumor with hot water ducted into and out of the cavity by pipes, or by localizing and heating the blood flowing through a limb containing the tumor. Diathermy and other radio frequency electric fields may also be employed to produce heating.
Such treatment methods have a number of disadvantages. They may not be effective against certain types of tumors, or against tumors located in certain portions of the body. Certain treatment methods, such as chemotherapy and radiation therapy, have well-publicized undesirable side effects, and with all known treatment methods it is difficult to avoid damage or destruction of healthy cells in the surrounding tissue.
There is a need for more effective methods of treating conditions such as tumors in living bodies, and that avoid the disadvantages of known methods, and it is to this end that the present invention is principally directed.